Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
Using data samples with an integrated luminosity of 4.5 fb(-1) collected by the BESIII detector at center-of-mass energies ranging from 4.66 GeV to 4.95 GeV, we study the processes of e(+) e(-) -> omega X(3872) and e(+) e(-) -> gamma X(3872). With the e(+) e(-) -> X(3872) process, the branching fraction ratio R = B(X(3872)->gamma J/psi)/B(X(3872)pi(+)pi(-)J/psi is measured to be 0.38 +/- 0.20(stat) +/- 0.01(syst) (R < 0.83 at 90% confidence level). In addition, we measure the ratio of the average cross section of e(+) e(-) -> omega X(3872) to e(+) e(-) -> omega chi(c1)(omega chi(c2)) to be sigma(omega X(3872))/sigma(omega Xc1)(sigma(omega X(3872))/sigma(omega Xc2)) = 5.2 +/- 1.0(stat) +/- 1.9(syst)(5.5 +/- 1.1(stat) +/- 2.4(syst)). Finally, we search for the process of e(+) e(-) -> gamma X(3872), and no obvious signal is observed. The upper limit on the ratio of the average cross section of e(+) e(-) -> gamma X(3872) to e(+) e(-) -> gamma X(3872) is set as sigma(gamma X)(3872)/sigma(omega X(3872)) < 0.23 at 90% confidence level.
Philippe Schwaller, Junwu Chen